I really hope this to be true because Super Mario 3D Land was a joke in the difficulty department.
We need a harder Super Mario Bros. game or else I'll have to play The Lost levels forever on All-Stars.

Quote:but I'm kinda skeptic to this one since it will be released so early.

They're probably reusing the engine of NSMB with 3DS adjustments ofcourse, and perhaps some new features.
The only thing they have to do besides that, is to create new levels, etc.

Quote:We need a harder Super Mario Bros. game

Mario games were never intended to be difficult in the first place. There are some hacks for NSBM like The Next Levels that definitely made the game a lot harder.
If you want difficulty, you should look elsewhere.